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~- <br />a <br />b. The regulations and their permit require that the <br />Division be notified. <br />c. Colowyo did not notify the Division of the topsoil <br />slide. It was noted by DMG during the inspection 3 <br />weeks after the slide occurred. <br />2. Colowyo states that the topsoil stockpile showed no signs of <br />instability. DMG inspection report from June 21, 1994 and <br />certified West Pit Fill Construction report dated January 1995 <br />discusses instability near the topsoil stockpile. Colowyo <br />should have been aware that additional instability was <br />probable in the location of the topsoil pile. <br />3. Colowyo states that extra measures were taken to locate the <br />topsoil pile away from the pond. As it was previously noted, <br />the topsoil pile should have been removed when the first slide <br />occurred in June 1994. It was noted at that point that the <br />slope was unstable. <br />Colowyo states that much of the landslide material was debris <br />under the stockpile rather than topsoil itself. The violation <br />addresses the failure to place topsoil on a stable surface. <br />The type of material that failed (topsoil vs. subsoil) is not <br />relevant to the damage caused to the perimeter slopes of the <br />sediment pond or potential loss of topsoil into the pond. <br />5. Colowyo states that available evidence suggests the integrity <br />of the pond is not in jeopardy. The Division has no evidence <br />that the pond is not in jeopardy nor has Colowyo provided such <br />information. Colowyo is currently monitoring the movement of <br />the slide. The topsoil slide has moved two feet since April <br />12, 1995. The integrity of the pond at this point in time is <br />unknown. <br />It should be noted that the sediment pond was designed for a <br />10-year event and only allowed for an additional .5 acre feet <br />of sediment storage (806 cy of material). A rough estimate of <br />the volume of material in the pond as a result of the slide is <br />1,800 cy of material. This does not include sediment that has <br />accumulated in the pond from when it was constructed roughly <br />a year ago. Based on this rough calculation of sediment, it <br />appears that the slide and the existing sediment in the pond <br />may have decreased the capacity of the pond. This issue was <br />not included in the violation, and will be addressed with the <br />submittal of the final certification of the pond. <br />Please let me know if you have any questions or need additional <br />information. <br />cc: Susan McCannon <br />Larry Routten <br />Jim Kiger/Colowyo Coal Co. L.P. <br />c:\colowyo\nov005 <br />